check out National Semiconductor's line of LDO / Ultra-LDO linear regulators:
**broken link removed**
sorry i can't link deeper for you, their URLs get kind of huge
they also have an online tool to help design switchmode converters, for the ultimate in efficiency
hehe their design tool had this to say
LP2986 5v ldo regulator with 200mA max current, 180mV drop-out, 38.5% typ efficency, 16vdc max input
LM5008 5v switch-mode regulator with 400mA max current, 92% typ efficiency, 95vdc max input